U.S. patent application number 15/196004 was filed with the patent office on 2017-01-12 for electrically driven pump.
This patent application is currently assigned to HANGZHOU SANHUA RESEARCH INSTITUTE CO., LTD.. The applicant listed for this patent is HANGZHOU SANHUA RESEARCH INSTITUTE CO., LTD.. Invention is credited to Junfeng BAO, Chen FANG, Lianjing NIU, Junchao ZHANG, Rongrong ZHANG.
Application Number | 20170009779 15/196004 |
Document ID | / |
Family ID | 56296595 |
Filed Date | 2017-01-12 |
United States Patent
Application |
20170009779 |
Kind Code |
A1 |
NIU; Lianjing ; et
al. |
January 12, 2017 |
ELECTRICALLY DRIVEN PUMP
Abstract
An electrically driven pump is provided, which includes an
impeller. The impeller includes an upper plate, blades and a lower
plate. The blades are formed on a lower surface of the upper plate,
the blades include first blades and second blades, and a length of
each of the first blades is greater than a length of each of the
second blades. The first blades are uniformly distributed along a
circumference of the upper plate. The first blades and the second
blades are distributed alternately in the circumferential
direction. The first blades each include a first head portion and a
first tail portion, the second blade includes a second head portion
and a second tail portion, and the first tail portion and the
second tail portion are aligned with outer edge of the upper plate.
The impeller arranged in such manner facilitates the improvement of
hydraulic efficiency and lift.
Inventors: |
NIU; Lianjing; (Hangzhou,
CN) ; ZHANG; Junchao; (Hangzhou, CN) ; ZHANG;
Rongrong; (Hangzhou, CN) ; BAO; Junfeng;
(Hangzhou, CN) ; FANG; Chen; (Hangzhou,
CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HANGZHOU SANHUA RESEARCH INSTITUTE CO., LTD. |
Hangzhou |
|
CN |
|
|
Assignee: |
HANGZHOU SANHUA RESEARCH INSTITUTE
CO., LTD.
Hangzhou
CN
|
Family ID: |
56296595 |
Appl. No.: |
15/196004 |
Filed: |
June 28, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04D 1/00 20130101; F04D
29/02 20130101; F28F 99/00 20130101; F04D 29/30 20130101; F28F
2250/08 20130101; F05B 2240/30 20130101; F05B 2280/6003 20130101;
F04D 13/06 20130101; F04D 29/242 20130101; F05B 2230/20 20130101;
F04D 29/5813 20130101; F04D 17/08 20130101; F04D 13/0606 20130101;
F04D 29/2222 20130101; F04D 25/0606 20130101; F05B 2230/22
20130101 |
International
Class: |
F04D 29/24 20060101
F04D029/24; F04D 13/06 20060101 F04D013/06; F04D 29/30 20060101
F04D029/30; F28F 99/00 20060101 F28F099/00; F04D 17/08 20060101
F04D017/08; F04D 1/00 20060101 F04D001/00; F04D 29/58 20060101
F04D029/58; F04D 25/06 20060101 F04D025/06; F04D 29/02 20060101
F04D029/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 6, 2015 |
CN |
201510393337.8 |
Claims
1. An electrically driven pump, comprising a rotor assembly, a
stator assembly, and a partition, wherein the rotor assembly and
the stator assembly are partitioned by the partition, the rotor
assembly comprises an impeller, the impeller comprises an upper
plate, blades and a lower plate, the blades are provided between
the upper plate and the lower plate, and the upper plate comprises
an upper surface and a lower surface, wherein, the blades and the
upper plate are integrally formed by injection molding, the blades
are located on the lower surface of the upper plate, the blades
comprise first blades and second blades, and each of the first
blades and the second blades comprises a camber, or a combination
of two or more than two cambers, or a combination of a camber and a
plane; a length of each of the first blades is greater than a
length of each of the second blades, the first blades are uniformly
distributed along a circumference of the upper plate, and the
second blades are uniformly distributed along the circumference of
the upper plate; a number of the first blades is the same as a
number of the second blades, and the first blades and the second
blades are distributed alternately along the circumferential
direction of the upper plate; and each of the first blades
comprises a first head portion and a first tail portion, each of
the second blades comprises a second head portion and a second tail
portion, an outer edge of the upper plate defines a first
circumference with a diameter of .PHI.1, the second head portions
of the second blades are located at a second circumference with a
diameter of .PHI.2, and the diameter .PHI.2 of the second
circumference ranges from 0.6 times to 0.75 times of the diameter
.PHI.1 of the first circumference.
2. The electrically driven pump according to claim 1, wherein each
of the first blades comprises a first side and a second side, the
first side is a concave side, and the second side is a convex side;
on the first circumference, a circular arc between the first sides
of the first blades adjacent to each other is a first circular arc,
and an arc length of the first circular arc is a first arc length
L1; each of the second blades comprises a third side and a fourth
side, and the third side is a concave side and the fourth side is a
convex side; and on the first circumference, a circular arc between
the first side of each of the first blades and the third side of
the respective adjacent second blade is a second circular arc, and
an arc length of the second circular arc is a second arc length L2;
and the second arc length L2 ranges from 0.35 times to 0.5 times of
the first arc length L1.
3. The electrically driven pump according to claim 2, wherein on
the first circumference, an included angle between, a tangential
line of the first side or an extending side of the first side of
each of the first blades, and a tangential line of the first
circumference, at an intersection of the first side or the
extending side of the first side with the first circumference, is a
first included angle .beta.1; an included angle between, a
tangential line of the third side or an extending side of the third
side of the second blade, and a tangential line of the first
circumference, at an intersection of the third side or the
extending side of the third side with the first circumference, is a
second included angle .beta.2; and the first included angle .beta.1
is greater than the second included angle .beta.2.
4. The electrically driven pump according to claim 3, wherein the
first included angle .beta.1 ranges from 20 degrees to 60 degrees,
and the second included angle .beta.2 is smaller than the first
included angle .beta.1 by 3 degrees to 10 degrees.
5. The electrically driven pump according to claim 1, wherein the
lower surface of the upper plate comprises a plane portion and a
camber portion, each of the first blades comprises a first segment
fixed to the plane portion and a second segment fixed to the camber
portion, a vertical distance between the first side and the second
side at the first segment is a thickness .epsilon.1 of each of the
first blades at the first segment, and the thickness .epsilon.1 of
each of the first blades at the first segment ranges from 0.8 mm to
2 mm.
6. The electrically driven pump according to claim 2, wherein the
lower surface of the upper plate comprises a plane portion and a
camber portion, each of the first blades comprises a first segment
fixed to the plane portion and a second segment fixed to the camber
portion, a vertical distance between the first side and the second
side at the first segment is a thickness .epsilon.1 of each of the
first blades at the first segment, and the thickness .epsilon.1 of
each of the first blades at the first segment ranges from 0.8 mm to
2 mm.
7. The electrically driven pump according to claim 3, wherein the
lower surface of the upper plate comprises a plane portion and a
camber portion, each of the first blades comprises a first segment
fixed to the plane portion and a second segment fixed to the camber
portion, a vertical distance between the first side and the second
side at the first segment is a thickness .epsilon.1 of each of the
first blades at the first segment, and the thickness .epsilon.1 of
each of the first blades at the first segment ranges from 0.8 mm to
2 mm.
8. The electrically driven pump according to claim 4, wherein the
lower surface of the upper plate comprises a plane portion and a
camber portion, each of the first blades comprises a first segment
fixed to the plane portion and a second segment fixed to the camber
portion, a vertical distance between the first side and the second
side at the first segment is a thickness .epsilon.1 of each of the
first blades at the first segment, and the thickness .epsilon.1 of
each of the first blades at the first segment ranges from 0.8 mm to
2 mm.
9. The electrically driven pump according to claim 5, wherein each
of the second blades is formed by extending from the plane portion
of the lower surface of the upper plate towards the lower plate, a
vertical distance between the third side and the fourth side of
each of the second blades is a thickness .epsilon.2 of each of the
second blades, and the thickness .epsilon.2 of each of the second
blades ranges from 0.6 times to 1 times of the thickness .epsilon.1
of each of the first blades at the first segment.
10. The electrically driven pump according to claim 1, wherein the
first head portion of each of the first blades is fixed to the
upper plate by injection molding, a straight line passing through a
fixing point, where the head portion is fixed to the upper plate,
and being in parallel with a central axis of the first
circumference is defined, an included angle between the head
portion and the straight line is defined as a front inclination
angle .theta.3 of each of the first blades, the front inclination
angle is referred to as a certain acute angle formed by the head
portion rotating from the central axis in a counterclockwise
direction, and the front inclination angle .theta.3 ranges from 20
degrees to 50 degrees.
11. The electrically driven pump according to claim 2, wherein the
first head portion of each of the first blades is fixed to the
upper plate by injection molding, a straight line passing through a
fixing point, where the head portion is fixed to the upper plate,
and being in parallel with a central axis of the first
circumference is defined, an included angle between the head
portion and the straight line is defined as a front inclination
angle .theta.3 of each of the first blades, the front inclination
angle is referred to as a certain acute angle formed by the head
portion rotating from the central axis in a counterclockwise
direction, and the front inclination angle .theta.3 ranges from 20
degrees to 50 degrees.
12. The electrically driven pump according to claim 3, wherein the
first head portion of each of the first blades is fixed to the
upper plate by injection molding, a straight line passing through a
fixing point, where the head portion is fixed to the upper plate,
and being in parallel with a central axis of the first
circumference is defined, an included angle between the head
portion and the straight line is defined as a front inclination
angle .theta.3 of each of the first blades, the front inclination
angle is referred to as a certain acute angle formed by the head
portion rotating from the central axis in a counterclockwise
direction, and the front inclination angle .theta.3 ranges from 20
degrees to 50 degrees.
13. The electrically driven pump according to claim 4, wherein the
first head portion of each of the first blades is fixed to the
upper plate by injection molding, a straight line passing through a
fixing point, where the head portion is fixed to the upper plate,
and being in parallel with a central axis of the first
circumference is defined, an included angle between the head
portion and the straight line is defined as a front inclination
angle .theta.3 of each of the first blades, the front inclination
angle is referred to as a certain acute angle formed by the head
portion rotating from the central axis in a counterclockwise
direction, and the front inclination angle .theta.3 ranges from 20
degrees to 50 degrees.
14. The electrically driven pump according to claim 5, wherein each
of the first blades comprises a connecting side, the connecting
side is arranged between the first head and the first side of each
of the first blades, and a distance from the connecting side to the
second side is smaller than the thickness .epsilon.1 of each of the
first blades at the first segment.
15. The electrically driven pump according to claim 6, wherein each
of the first blades comprises a connecting side, the connecting
side is arranged between the first head and the first side of each
of the first blades, and a distance from the connecting side to the
second side is smaller than the thickness .epsilon.1 of each of the
first blades at the first segment.
16. The electrically driven pump according to claim 7, wherein each
of the first blades comprises a connecting side, the connecting
side is arranged between the first head and the first side of each
of the first blades, and a distance from the connecting side to the
second side is smaller than the thickness .epsilon.1 of each of the
first blades at the first segment.
17. The electrically driven pump according to claim 1, wherein each
of the first tail portion and the second tail portion is aligned
with the outer edge of the upper plate; on the first circumference,
a side of each of the first blades which is not in direct contact
with the upper plate is a free end of each of the first blades, a
distance from the free end of each of the first blades to the lower
surface of the upper over plate is an outlet height H1 of each of
the first blades, a side of each of the second blades which is not
in direct contact with the upper plate is a free end of each of the
second blades, a distance from the free end of each of the second
blades to the lower surface of the upper plate is an outlet height
H2 of each of the second blades, and the outlet height H1 of each
of the first blades is greater than the outlet height H2 of each of
the second blades.
18. The electrically driven pump according to claim 2, wherein each
of the first tail portion and the second tail portion is aligned
with the outer edge of the upper cover plate; on the first
circumference, a side of each of the first blades which is not in
direct contact with the upper cover plate is a free end of each of
the first blades, a distance from the free end of each of the first
blades to the lower surface of the upper over plate is an outlet
height H1 of each of the first blades, a side of each of the second
blades which is not in direct contact with the upper cover plate is
a free end of each of the second blades, a distance from the free
end of each of the second blades to the lower surface of the upper
cover plate is an outlet height H2 of each of the second blades,
and the outlet height H1 of each of the first blades is greater
than the outlet height H2 of each of the second blades.
19. The electrically driven pump according to claim 3, wherein each
of the first tail portion and the second tail portion is aligned
with the outer edge of the upper cover plate; on the first
circumference, a side of each of the first blades which is not in
direct contact with the upper cover plate is a free end of each of
the first blades, a distance from the free end of each of the first
blades to the lower surface of the upper over plate is an outlet
height H1 of each of the first blades, a side of each of the second
blades which is not in direct contact with the upper plate is a
free end of each of the second blades, a distance from the free end
of each of the second blades to the lower surface of the upper
plate is an outlet height H2 of each of the second blades, and the
outlet height H1 of each of the first blades is greater than the
outlet height H2 of each of the second blades.
20. The electrically driven pump according to claim 4, wherein each
of the first tail portion and the second tail portion is aligned
with the outer edge of the upper plate; on the first circumference,
a side of each of the first blades, which is not in direct contact
with the upper plate, is a free end of each of the first blades, a
distance from the free end of each of the first blades to the lower
surface of the upper over plate is an outlet height H1 of each of
the first blades, a side of each of the second blades which is not
in direct contact with the upper plate is a free end of each of the
second blades, a distance from the free end of each of the second
blades to the lower surface of the upper plate is an outlet height
H2 of each of the second blades, and the outlet height H1 of each
of the first blades is greater than the outlet height H2 of each of
the second blades.
Description
CROSS REFERENCE OF RELAYED APPLICATION
[0001] The present application claims the priority to Chinese
Patent Application No. 201510393337.8, titled "IMPELLER,
CENTRIFUGAL PUMP, ELECTRICALLY DRIVEN PUMP", filed on Jul. 06,
2015, with the State Intellectual Property Office of the People's
Republic of China, the content of which is incorporated herein by
reference in its entirety.
FIELD
[0002] This application relates to a component in a heat
circulating system.
BACKGROUND
[0003] In recent decades, electrically driven pumps have been
widely used in heat circulating systems. Currently, the heat
circulating systems are developed in a trend of high performance,
and compactification, accordingly, the electrically driven pump has
a limited mounting space, and has requirements for high
performance. Since the electrically driven pump has a small overall
dimension and a small volume, the electrically driven pump includes
an impeller, a diameter of the impeller is required to be small, in
this case, a conventional impeller can hardly meet the requirements
for high lift and high efficiency at low specific speed and low
flow rate.
[0004] Therefore, it is necessary to improve the conventional
technology, to address the above technical issues.
SUMMARY
[0005] An object of the present application is to provide an
electrically driven pump, which may achieve the required flow rate
and lift at a low speed, and may achieve a high hydraulic
efficiency.
[0006] To achieve the above objects, the following technical
solutions are adopted in the present application. An electrically
driven pump includes a rotor assembly, a stator assembly, and a
partition. The rotor assembly and the stator assembly are
partitioned by the partition. The rotor assembly includes an
impeller, the impeller includes an upper plate, blades, and a lower
plate, and the blades are provided between the upper plate and the
lower plate. The upper plate includes an upper surface and a lower
surface, the blades and the upper plate are integrally formed by
injection molding, and the blades are located on the lower surface
of the upper plate. The blades include first blades and second
blades, and each of the first blades and the second blades includes
a camber, or a combination of two or more than two cambers, or a
combination of a camber and a plane. A length of each of the first
blades is greater than a length of each of the second blades, the
first blades are uniformly distributed along a circumference of the
upper plate, and the second blades are uniformly distributed along
the circumference of the upper plate. A number of the first blades
is the same as a number of the second blades, and the first blades
and the second blades are distributed alternately along the
circumferential direction of the upper plate. Each of the first
blades includes a first head portion and a first tail portion, and
each of the second blades includes a second head portion and a
second tail portion. An outer edge of the upper plate defines a
first circumference with a diameter of .PHI.1, the second head
portions of the second blades are located on a second circumference
with a diameter of .PHI.2, and the diameter .PHI.2 of the second
circumference ranges 0.6 times to 0.75 times of the diameter .PHI.1
of the first circumference.
[0007] Compared with the conventional technology, the electrically
driven pump according to the present application includes the
impeller, the impeller includes the upper plate, the blades and the
lower plate, and the blades are arranged between the upper plate
and the lower plate. The blades include the first blades and the
second blades, the outer edge of the upper plate defines the first
circumference with a diameter of .PHI.1, the head portions of the
second blades are located on the second circumference with a
diameter of .PHI.2, and the diameter of the second circumference
ranges from 0.6 times to 0.7 times of the diameter of the first
circumference. The impeller arranged in such manner facilitates
achieving a required flow rate and lift by the electrically driven
pump, and facilitates the improvement of a hydraulic efficiency of
the electrically driven pump.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a schematic sectional view showing the structure
of an electrically driven pump according to an embodiment of the
present application;
[0009] FIG. 2 is a schematic exploded view showing the structure of
a rotor assembly in FIG. 1;
[0010] FIG. 3 is a schematic perspective view showing the structure
of the rotor assembly in FIG. 1;
[0011] FIG. 4 is a schematic orthographic view showing the
structure of the rotor assembly in FIG. 2 viewed from a top;
[0012] FIG. 5 is a schematic sectional view showing the structure
of the rotor assembly in FIG. 2;
[0013] FIG. 6 is a schematic front view showing the structure of a
first part in FIG. 2;
[0014] FIG. 7 is a schematic perspective view showing the structure
of a second part in FIG. 2; and
[0015] FIG. 8 is a schematic top view showing the structure of the
second part in FIG. 7.
DETAILED DESCRIPTION
[0016] The present application is further described in conjunction
with drawings and embodiments hereinafter.
[0017] FIG. 1 is a schematic view showing the structure of an
electrically driven pump 100. The electrically driven pump 100
includes a first housing 10, a partition 20, a second housing 30, a
shaft 40, a rotor assembly 50, a stator assembly 60, a circuit
board 70 and a heat dissipating assembly 80. An inner chamber of
the electrically driven pump includes a space defined by the first
housing 10 and the second housing 30, and the partition 20 divides
the inner chamber of the electrically driven pump into a first
chamber 91 and a second chamber 92. The first chamber 91 allows
working medium to flow through, and the rotor assembly 50 is
arranged in the first chamber 91. No working medium flows through
the second chamber 92, and the stator assembly 60 and the circuit
board 70 are arranged in the second chamber 92. The shaft 40 is
fixed to the partition 20 by injection molding. The rotor assembly
50 is rotatable about the shaft 40. The rotor assembly 50 is
separated from the stator assembly 60 by the partition 20. The
stator assembly 60 is electrically connected to the circuit board
70. The circuit board 70 is connected to an external circuit by a
socket-connector. The heat dissipating assembly 80 is configured to
transfer and dissipate heat generated by the circuit board 70, and
the heat dissipating assembly 80 is fixedly mounted to the second
housing 30. In this embodiment, the electrically driven pump 100 is
an inner rotor type electrically driven pump, and the inner rotor
type electrically driven pump is referred to as a pump in which the
rotor assembly 50 is arranged to be closer to the shaft 16 than the
stator assembly 60 if the shaft 40 is taken as a central axis. In
this embodiment, the shaft 40 is arranged to be fixed with respect
to the partition 20, and the rotor assembly 50 is rotatable with
respect to the shaft 40. Of course, the shaft 40 may also rotate
with respect to the partition 20 by means of the shaft sleeve, and
the rotor assembly 50 may be fixed to the shaft 40 and rotate along
with the shaft 40.
[0018] FIGS. 2 to 9 are schematic views showing the structure of
the rotor assembly 50. Referring to FIG. 2, the rotor assembly 50
includes two parts of injection molded members, respectively a
first part 51 and a second part 52 which are fixed to each other by
welding. The first part 51 includes an upper plate 11 and blades
12, and the first part 51 is integrally formed by injection
molding. In an embodiment, the material for the injection molding
is a mixture including polyphenylene sulfide (abbreviated as PPS)
and glass fiber. The second part 52 includes a permanent magnet 21,
and a lower plate 13. The second part 52 is formed by injecting
molding using a mixed material containing the PPS and carbon fiber
and taking the permanent magnet 21 as an injection molding insert.
In addition, the injection molding material may also be other
thermoplastic materials having a relatively good mechanical
performance. Referring to FIG. 3, the rotor assembly 50 includes an
impeller 1 and a rotor 2 according to function. The impeller 1
includes the upper plate 11, the blades 12 and the lower plate 13.
The rotor 2 includes the permanent magnet 21. In this embodiment,
the permanent magnet 21 is substantially of an annular structure,
and the permanent magnet 21 is formed by injection molding or
sintering, and of course, the rotor 2 may also be in other
structural forms. In this embodiment, portions of the impeller 1
except the upper plate 11 and the blades 12 are integrally formed
with the permanent magnet 21 by injection molding, and the integral
piece formed by injection molding is used in the electrically
driven pump. The impeller 1 may also be formed separately and may
be used in other centrifugal pumps, and is not limited to the
electrically driven pump, and is also not limited to be integrally
formed with the rotor 2.
[0019] Referring to FIG. 3, the impeller 1 includes an inlet 15,
the upper plate 11, the blades 12, the lower plate 13, and an
outlet 14. The blades 12 are arranged between the upper plate 11
and the lower plate 13. The inlet 15 of the impeller 1 is formed by
the upper plate 11. Multiple outlets 14 of the impeller 1 are
formed at an outer periphery of the upper plate 11 between adjacent
blades 12 and between the upper plate 11 and the lower plate 13.
Multiple impeller passages are formed between adjacent blades 12,
and each of the impeller passages is in communication with the
inlet 15 and one of the outlets 14 of the impeller 1. An upper side
and a lower side of each of the impeller passages are closed by the
upper plate 11, the lower plate 13, and side walls of blades at the
two lateral sides of the impeller passage.
[0020] Referring to FIGS. 3, 5, and 6, the upper plate 11 is
substantially of an annular shape. The upper plate 11 includes a
plane portion 111 and a camber portion 112. The plane portion 111
includes an upper plane portion 1111 and a lower plane portion
1112. The camber portion 112 includes a first camber portion 1121
and a second camber portion 1122. The first camber portion 1121 is
smoothly transited to the upper plane portion 1111, the second
camber portion 1122 is smoothly transited to the lower plane
portion 1112, and the inlet 15 of the impeller 1 is formed by
encircling of the camber portion 112. The blades 12 are integrally
formed with the lower plane portion 1112, or the lower plane
portion 1112 and the second camber portion 1122, of the upper plate
11 by injection molding. Referring to FIG. 3, at a side wall of the
inlet 15 of the impeller 1, the impeller 1 includes a vertical
portion 113 tangential to the side wall of the inlet 15 of the
impeller 1, actually, the vertical portion 113 is a partial
connecting portion where the upper plate 11 is connected to the
blades 12, thus facilitating demolding of the first part 51 of the
impeller 1. In this embodiment, the plane portion 111 is set at a
certain angle with respect to the horizontal plane, and the blades
12 are arranged to be substantially perpendicular to the horizontal
plane. An outer edge of the upper plate 111 defines substantially a
first circumference with a diameter of .PHI.1, and a diameter of
the impeller is equal to the diameter of the first circumference,
and is also equivalent to an outer diameter of a circle defined by
tail portions of outer edges of the blades 12.
[0021] Referring to FIGS. 2 and 6, the blades 12 include first
blades 121 and second blades 122. The first blades 121 and the
second blades 122 are each in a circular-arc shape. A length of
each of the first blades 121 is greater than a length of each of
the second blades 122. The first blades 121 are distributed at
equal intervals along a circumference of the impeller 1, and the
second blades 122 are distributed at equal intervals along the
circumference of the impeller 1.
[0022] The number of the first blades 121 is the same as the number
of the second blades 122. The first blades 121 and the second
blades 122 are distributed alternately along the circumference of
the impeller 1, i.e., each of the second blades 122 is arranged
between adjacent first blades 121. Each of the first blades 121 and
the second blades 122 may each include a camber, or a combination
of two or more than two cambers, or a combination of a camber and a
plane.
[0023] Referring to FIG. 6, the first blades 121 are formed
integrally with the lower plane portion 1112 and the second camber
portion 1122 of the upper plate 11 by injection molding. Each of
the first blades 121 includes a first segment 3 integrally formed
with the second camber portion 1122 by injection molding, and a
second segment 4 integrally formed with the lower plane portion
1112 by injection molding. The first segment 3 includes a head
portion 31, a first bottom 32, a first concave side 33, and a first
convex side 34. The second segment 4 includes a second bottom 42, a
second concave side 43, a second convex side 44, and a tail portion
45. The head portion 31 protrudes into the inlet 15 of the impeller
1. The head portion 31 is a start end of the first blade 121, and
the tail portion 45 is a terminal end of the first blade 121. An
arc length between the head portion 31 and the tail portion 45 is
the length of the first blade 121. In this embodiment, the first
concave side 33 and the second concave side 43 form a first side of
the first blade 121. The first convex side 34 and the second convex
side 44 form a second side of the first blade 121. The head portion
31 is a first head of the first blade 121, and the tail portion 45
is a first tail portion of the first blade 121. On the first
circumference, a first circular arc with a length of L1 is defined
between intersections of, the second concave sides 43 of adjacent
first blades 121, with the first circumference. The length L1 of
the first circular arc is equal to a length of each circular arc
defined by equally dividing the first circumference into parts with
the number of the first blades 121. In this embodiment, the number
of the first blades 121 is five, and the length L1 of the first
circular arc is equal to a length of each circular arc defined by
equally dividing the first circumference into five parts.
[0024] Referring to FIG. 2, a portion where the head portion 31 is
located is a flow guiding part of the first blade 121. The working
medium enters into the impeller 1 through the inlet 15 of the
impeller 1 and is guided into a circulating passage between
adjacent first blades 121 via the head portion 31, and the head
portion 31 is fixed to an inner side wall of the inlet 15 by
injection molding. The first segment 3 further includes a
connecting side 1216 arranged between the head portion 31 and the
first concave side 33. A distance from the connecting side 1216 to
the first convex side 34 is smaller than a distance from the first
concave side 33 to the first convex side 34. In this way, the
connecting side 1216 allows a thickness of each of the first blades
121 at a section corresponding to the connecting side 1216 to be
decreased, thus, a gap between the first blades 121 at the portion
from the head portion 31 to a terminal position of the connecting
side 1216 may be increased, which may reduce a flowing resistance
to the working medium, and allows the working medium to smoothly
flow.
[0025] Referring to FIGS. 2 and 3, the head portion 31 protrudes
into the inlet 15 of the impeller 1. A straight line is defined by
passing through a fixing point 311 at which the first blade 121 is
fixed to the side wall of the impeller inlet 15 and being in
parallel with a center line of the side wall of the inlet 15 of the
impeller 1, an included angle between the head portion 31 and the
straight line is a front inclination angle 03 ranging from 20
degrees to 50 degrees. A free end of the head portion 31 inclines
to a central axis direction of the impeller inlet 15 by 20 degrees
to 50 degrees, in this way, the part where the head portions 31 are
located can better restrict flowing of the working medium.
[0026] A thickness of each of the first blades 121 is represented
by .epsilon.1, and the thickness .epsilon.1 of the first blade 121
is referred to as a vertical distance between the first side and
the second side of the first blade. In this embodiment, considering
that the material for forming the blade by injection molding has a
certain brittleness, the first blade 121 may be fractured, broken
or damaged if it is too thin, therefore, the value of the thickness
.epsilon.1 of the first blade according to the present application
is set relatively large. In this embodiment, the thickness
.epsilon.1 of the first blade generally ranges from 0.8 mm to 2 mm.
In this embodiment, for facilitating demolding, the first side and
the second side are provided with small draft angles respectively,
since the draft angles are very small, a height difference
generated by the draft angles may be neglected when compared to the
height of the first blade 121
[0027] Referring to FIG. 6, on the first circumference, at an
intersection of the second concave side 43 or an extending side of
the second concave side of the first blade 121 with the first
circumference, an included angle between a tangential line of the
second concave side 43 or the extending side of the second concave
side 43, and a tangential line of the first circumference at the
intersection is a first included angle .beta.1 of the first blade
121. The first included angle .beta.1 of the first blade 121 ranges
from 20 degrees to 60 degrees. In this embodiment, the impeller 1
of the electrically driven pump 100 is a low specific speed
centrifugal impeller, and a large blade angle is generally
configured to reduce a frictional loss of disk as much as possible,
thus ensuring the efficient operation of the electrically driven
pump. However, the blade angle .beta.1 that is large may adversely
affect the performance stability of the impeller, thus in order to
acquire a stable performance curve and preventing overloading, for
the structure of the impeller 1 according to this embodiment, the
first included angle .beta.1 of the first blade 121 according to
the present application ranges from 20 degrees to 60 degrees.
[0028] Referring to FIGS. 2 and 6, each of the first blades 121
includes a bottom, and the bottom includes the first bottom 32 and
the second bottom 42. From a central portion of the upper plate to
an edge of the upper plate, a distance from the second bottom 42 to
the upper plate 11 gradually decreases. On the first circumference,
the tail portion 45 is arranged to be aligned with an outer edge of
the upper plate 11 of the impeller. The tail portion 45 is a small
section of a cylindrical surface, or the tail portion 45 is a
portion of a cylindrical surface defined by extending the outer
edge of the upper plate 11. The tail portion 45 connects the second
concave side 43 and the second convex side 44 at an end of the
first blade 121. The tail portion 45 has a height which is a
smallest height of the first blade 121, and the height of the first
blade 121 at the tail portion 45 is defined as an outlet height H1
of the first blade 121. The bottom of the first blade 121 is
provided with a connecting structure fixed to the lower plate 13.
The connecting structure includes a cylindrical protrusion 321 and
protruding ribs 322. A height of each of the protruding ribs 322
protruded is smaller than a height of the cylindrical protrusion
321, and the protruding ribs 322 are arranged at intervals along
the bottom. Each first blade 121 is provided with one cylindrical
protrusion 321 and multiple protruding ribs 322. The free end of
the first blade is namely the bottom of the first blade.
[0029] Referring to FIG. 6, the second blade 122 is fixed to the
plane portion 111 of the upper plate 11 by injection molding. The
second blade 122 starts from a second circumference with a diameter
of .PHI.2, and terminates at the first circumference with the
diameter of .PHI.1, and the diameter .PHI.2 of the second
circumference ranges from 0.6 times to 0.75 times of the diameter
.PHI.1 of the first circumference. The second blade 122 includes a
front end 1221, a concave side 1222, a convex side 1223, a rear end
1224 and a bottom 1225 of the second blade. The front end 1221 is
arranged at the second circumference with the diameter of .PHI.2,
and the rear end 1224 is arranged at the first circumference with
the diameter of .PHI.1. On the first circumference, at an
intersection of the concave side 1222 or an extending side of the
concave side with the first circumference, an included angle
between a tangential line of the concave side 1222 or the extending
side of the concave side, and a tangential line of the first
circumference is a second included angle .beta.2 of the second
blade 122. In this embodiment, the front end 1221 is a second head
portion of the second blade 122, and the rear end 1224 is a second
tail portion of the second blade 122, the concave side 1222 is a
third side of the second blade 122, and the convex side 1223 is a
fourth side of the second blade 122. The second included angle
.beta.2 of the second blade 122 is smaller than or equal to the
first included angle .beta.1 of the first blade 121. In this
embodiment, and the second included angle .beta.2 of the second
blade 122 is smaller than the first included angle .beta.1 of the
first blade 121 by 3 degrees to 10 degrees. Except portions at the
front end 1221 and the rear end 1224, a thickness .epsilon.2 of the
second blade ranges from 0.6 times to 1 times of the thickness
.epsilon.1 of the first blade, and if the central axis of the inlet
of the impeller is taken as a center of circle, a height of the
second blade is smaller than or equal to a height of the first
blade at the same portion of the circle. The free end of the second
blade is namely the bottom of the second blade.
[0030] Referring to FIGS. 2 and 6, from the front end 1221 to the
rear end 1224, a distance from the bottom 1225 of the second blade
122 to the lower surface of the upper plate gradually decreases,
and is the smallest at the first circumference. An outlet height H2
of the second blade is defined as the smallest distance from the
second blade bottom 1225 to the lower surface of the upper plate at
the first circumference. In this embodiment, a height of the second
blade is smaller than a height of the first blade at the same
position of the circle, and the outlet height H2 of the second
blade is smaller than the outlet height H1 of the first blade.
Thus, after the impeller is assembled, a certain gap or a small gap
is formed between the second blade bottom 1225 and the lower plate
13. On the first circumference, a second circular arc with a length
of L2 is defined between a tangential line of the concave side 1222
of the second blade, and a tangential line of the second concave
side 43 of a first blade adjacent to the second blade, and the arc
length L2 of the second circular arc ranges from 0.35 times to 0.5
times of the arc length L1 of the first circular arc.
[0031] Referring to FIGS. 7 and 8, the lower plate 13 includes an
upper side 131 and a lower side. The lower plate 13 is fixedly
connected to the bottoms of the blades 12 via the upper side 131,
the upper side 131 of the lower plate 13 is configured to have a
shape matching with the shape of the bottoms of the blades 12, and
the lower side of the lower plate 13 is substantially a horizontal
plane. Blade mounting grooves 1311 are formed in the upper side 131
of the lower plate 13, and the number of the blade mounting grooves
1311 is the same as the number of the first blades 121. A stripe
protrusion 133 is provided in each of the blade mounting grooves
1311, and a small mounting hole 134 extending through the lower
plate 13 is further provided in at least one of the blade mounting
grooves 1311, and the cylindrical protrusion 321 is provided on the
bottom of a first blade corresponding to the at least one blade
mounting groove 1311 provided with the small mounting hole 134 so
as to fit the small mounting hole 134. In this embodiment, each of
the blade mounting grooves 1311 is provided with one small mounting
hole 134. During assembly of the impeller 1, each of the
cylindrical protrusions 321 of the bottoms 1211 of the first blades
121 is inserted into a respective small mounting hole 134, and each
of the bottoms 1211 of the first blades 121 is inserted into a
respective blade mounting groove 1311, and the first blades 121 are
fixed to the lower plate 13 by ultrasonic welding, thus forming the
impeller 1. An impeller mounting hole 136 is formed in the lower
plate 13, and the impeller 1 is sleeved on an outer surface of the
shaft 40 via the impeller mounting hole 136.
[0032] It should be noted that, the above embodiments are only
intended for describing the present application, and should not be
interpreted as a limitation to the technical solutions of the
present application. Although the present application is described
in detail in conjunction with the above embodiments, it should be
understood by those skilled in the art that, modifications or
equivalent substitutions may still be made to the present
application by those skilled in the art; and any technical
solutions and improvements of the present application without
departing from the spirit and scope thereof also fall into the
scope of the present application defined by the claims.
* * * * *